Venetian blinds are a type of window covering comprising horizontal slats, one above another. The slats are typically suspended between an upper rail and a bottom rail by cords. One cord, the ladder cord, is used to control the rotation of the blinds. The other cord, the raising cord, is used to raise and lower the slats. The ladder cord allows the slats to rotate or tilt approximately 180 degrees in either direction. At one extreme the slats are rotated such that they overlap with one side of the slats facing inward and the other sides of the slats facing outward. At the other extreme, the opposite sides of the slats face inward and outward. When the lift cord is pulled, the bottom rail moves towards the upper rail, causing the slats to be stacked one on top of the other.
In most prior art Venetian blinds, an external tilting wand is used to control an operating mechanism that causes the rotation of the slats and an external lift cord is used to control the height of the bottom rail. These components are visible and not aesthetically pleasing. Moreover, the cords pose a choking or strangulation hazard for children. While some prior art Venetian blinds have removed the external tilting wand or lift cord, no such prior art devices have eliminated the needs of the external tilting wand, as well as the external lift cord without severely limiting the function of the blind. Therefore, it is desirable to provide an aesthetically pleasing and safe window blind that does not include either an external tilting wand or an external lift cord.
Therefore, there is a need for an actuator mechanism for controlling the movement of a window covering, such as a Venetian blind, that overcomes the foregoing problems.